Photo: Haidlmair GmbH

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Photo: Haidlmair GmbH Photo 1: Plastic pallets with anti-slip strips integrated in the top and bottom surface provide extra user safety with goods logistics, particularly in harsh environmental

1 Photo: Haidlmair GmbH Photo 1: Plastic pallets with anti-slip strips integrated in the top and bottom surface provide extra user safety with goods logistics, particularly in harsh environmental conditions, e.g. in the rain or at ice and snow. Maintaining position The global goods logistics does not only take place at fair weather and inside buildings, but to a large extent outdoor and in bad weather. Moisture in any form, whether rain, snow and ice or spray water at sea, brings goods and pallets to slip and slide, causing dangers and loss. The solution for the problem is a plastic pallet with non-skid strips on the top and bottom made of TPE, firmly attached by the twocomponent injection moulding. Since such logistics conditions are particularly common in northern Europe, it was obvious that this kind of pallet had been developed by a Norwegian company, the Interpallet AS in Rjukan, three hours' drive west of Oslo. The required large-size injection moulding tool and the application technology comes from the Austrian toolmaker Haidlmair. Speed and safety are top important in goods logistics. It can only be quick if the pallets used as goods carrier hold and secure the cargo firmly respectively the pallet rests firmly on the forks of the

2 pallet carrier. In both cases it depends on the friction coefficient between the surface and partner part. Is the friction too low, a additional holding equipment like straps or a box-type pallet have to be used. Both cases require additional actions in the movement of goods, reducing the productivity. The friction coefficient of wooden pallets has an edge over the plastic pallets, but this is the less ahead the more the pallet is exposed to moisture, ice and snow. Plastic pallets, mostly made of PP are ahead with their excellent resistance to moisture of any kind, mechanical stress in a wide temperature range, but have smooth surfaces with a low friction coefficient. This was the starting position for the product development of the Norwegian start-up company Interpallet AS in Rjukan. Managing director Helge Almestad recalls: "We were aware that a new plastic pallet design would be accepted in Scandinavia only if we offer solutions for the problems summarized above. For us the only solution in question was a pallet with local antislip-strips or coatings made of injectionmouldable TPE on both the product carrier side and the forklift side. The TPE should be soft and abrasion resistant at room temperature and also down to minus 30 C and be firmly bonded with the PP-Structure of the pallet body. Finally, the coating should not be applied by any post treatment operation, but come as ready to used product out of a two-component injection moulding machine. Now, we set out to find a feasible design. We discussed our concept drawings with several major machine manufacturers and tool makers, until we finally found the right partner in the Austrian companies Haidlmair and Engel. The toolmaker Haidlmair impressed us with his already realized injection moulds for large container and with his suggestions for transferring our pallet design in an economically viable production solution. And: There was a lot to be discussed before the mould construction works were on track. Comparatively, a routine affair was the design of the injection mould for the 800 x 1200 mm Euro pallet for 1,000 kg payload. The grid pattern design had been optimized with a load simulation software. A PP-grade with good low temperature impact toughness had been chosen. At the end of the product weight was 17.5 kg. For injection the PP-type with a very low MFI the injection system had been specified with a 10-nozzle hotrunner system. The mould cavity for the pallet is equipped with hydraulically actuated side coves on all four sides to release the side faces, two of the side cores integrating each additional two side cores for releasing the fork-holes. That was just as construction routine, such as the ejector system consisting of a combination of four central block ejectors and round ejectors assisting in the peripheral areas, as well as the integration of a suitable cooling system for a cycle time of approximately 90 seconds (Fig. 2). Here ended the routine job. The two-sided addition of relatively small amounts of TPE on one so large and bulky base part was new territory.

3 2-component injection moulding without large movements The challenge was to find a method for adding on all nine feet structures auf the pallet on each side 2 mm with TPE coatings to each rip wall. In addition, linear TPE areas should add to six rip over the full length of the pallet, but both at the top and bottom of the pallet (Fig. 3a + b). Overall, the volume calculation resulted in almost exactly cm3 PP and just 129 cm3 TPE at the top and 86 cm3 at the bottom surface of the pallet. Combining such disproportionate amounts of material seemed to be impossible at first site and required some feasibility studies, which had been established in close cooperation with Engel Austria as the selected machine supplier. Their machine system with 2- platen clamping unit is the fundamental precondition for the feasibility. Based on the mould size and weight a clamping unit with 3200 tons clamp force had to be chosen Since this machine concept offers almost all the freedom in the placement of additional injection units around the mould, it is part of the solution for the mould design. The clamping unit concept allowed for positioning of two separate small injection units for adding the TPE with the second injection process, one on top of the fixed mould side, the second diametrically opposite instead of the central standard ejector (Fig.4a + b). Each of these injection units is feeding a separate hotrunner system, one with nine injection nozzles, the second with 9+4 nozzles. Haidlmair project manager Guenther Auer recalls details of the mould design process: "A particularly sensitive point in the requirements specification was to cover the four corner areas of the pallet on top with TPE. These areas were almost impossible to reach by the TPE flow path. A pallet design adaption and the addition of four miniature side cores, which open and close the respective area at a length of about 10 mm to 2 mm rib width provided the solution at last. To resolve the puzzle of how exactly the TPE strips come on the palette, it should be mentioned that after the injection and cooling of the pallet the mould is opened in two sequential steps, first on the fixed side and after that on the moving mold half each by two millimeters. Accordingly the TPE is injected in two sequentially operations. Subsequently the mould fully opened, side cores and ejectors actuated and the pallet demoulded. An articulated robot takes the pallet and passes it to a post cooling line, transferring them to a stacking station (Fig. 5). The TPE injection extends the cycle time by 10 sec only from 90 to 110 seconds. Target achieved The result of this two-year development project is very presentable. There is a hitherto unique pallet that is suitable for use in rack systems with loads up to 1000 and also suitable for the secure

4 logistics, especially in harsh and humid environment. Interpallet boss Helge Almestad summarizes the project from his point of view (Fig. 6): "To bring my vision of the safe pallet to life, we needed competent cooperation partners, especially for the transformation of the sophisticated product idea into a producible moulding. The designers and toolmakers of Haidlmair have fulfilled these expectations and contributed greatly to the success of this project. Contact at Messrs. Haidlmair: Günther Auer, Project manager guenther.auer@haidlmair.at Contact at Messrs. Interpallet: Helge Almestad, General manager post@interpallet.no Author: Reinhard Bauer / TECHNOKOMM office@technokomm.at about Haidlmair: Haidlmair GmbH, Werkzeugbau The tool Haidlmair GmbH, founded in 1979, is the parent company in a privately owned group of companies with currently seven companies and 500 employees, generating sales of around EUR 60 million. The core business of the parent plant in Nussbach is the production of injection molds with a focus on the full range of vessels - from the beverage case to the pallet, complemented by large-scale forms for pallets The companies Mould & Matic and EMO Extrusion Molding, both in Micheldorf and HTM / Szekesksfehervar are injection molds for parts packaging, specialized extrusion dies for the production of films and sheets, and general injection molds. Three other companies in the group are service companies for the maintenance of shape and component manufacturing Haidlmair GmbH, Werkzeugbau Haidlmairstraße 1 A 4542 Nußbach Tel: +43 (0) Fax: +43 (0) office@haidlmair.at Internet:

about Interpallet Interpallet AS The company Interpallet is a start-up company based on the product idea to mould Euro-pallets made of plastic for use on ships and in land logistics under rainy or

5 about Interpallet Interpallet AS The company Interpallet is a start-up company based on the product idea to mould Euro-pallets made of plastic for use on ships and in land logistics under rainy or wintry conditions safer and more usable. As a solution, a 2-component pallet with integrated non skid TPE inserts has been developed which can be produced by injection moulding. The serial production started in Adresse: Svaddenveien 171 No-3660 Rjukan - Norway Tel.: Fax: epost@interpallet.no Internet: Photos: Photo: Haidlmair GmbH Photo 2: Developed by Haidlmair GmbH, the 2K injection moulding tool is designed for production on an injection moulding machine with 32,000 kn clamping force. It integrates three hot runner systems and complex kinematics for the sequential combination of the PP-pallet body with the TPE-strips.

6 Photo: Haidlmair GmbH Photo.3a+b: The 2-K-pallet of Interpallet integrates non skid strips of TPE both at the top and at the bottom. This is achieved by adding to the ribs of the pallet structure at selected points (green areas) 2 mm of TPE on both sides of the pallet.

Their nozzles are directly connected to the PP-hot runner.

7 Photo: Interpallet AS Photo 4a+b: For injection moulding the 2-K-pallet, four injection units are used: two parallel main aggregates (Photo 4b) for injection the PP for the pallet body. Their nozzles are directly connected to the PP-hot runner. The TPE-strips at the top and bottom of the pallet are injected with of two separate small-injection units (Photo 4a) attached both to fixed an the moving machine platen.

8 Photo: Haidlmair GmbH Photo 5: Tool and machine are designed for automatic operation. The manipulation of the 17.5 kg pallet is done by an industrial robot, which transfers it to a secondary cooling line, conveying them to a stacking station.

9 Photo: Interpallet AS Photo 6: The head of the pallet manufacturer Interpallet, Helge Almestad, presents with pride the result of a cooperation project with the Austrian toolmaker Haidlmair.

CRATES, BOXES, CONTAINERS, PALLETS MADE OF PLASTIC ARE OUR WORLD

CRATES, BOXES, CONTAINERS, PALLETS MADE OF PLASTIC ARE OUR WORLD > FROM THE BOTTLE CRATE TO THE PALLET-BOX, ...BUT ALSO CHASSIS OF LARGE HOME APPLIANCES OR THE FRAMES AND HOUSINGS OF TV SETS AND COMPUTER